Glaucoma, a widespread, chronic disease, is a leading cause of blindness. In the most prevalent form of glaucoma, primary open-angle glaucoma (POAG), increased intraocular pressure (IOP) is the most common risk factor. Results from large clinical trials indicate that decreasing IOP in glaucoma patients delays the development of vision loss (Palmberg, 2002). Even glaucoma patients with IOPs in the normal range benefit from decreasing their IOP. Currently, numerous pharmacological and surgical approaches are employed to reduce IOP in glaucoma patients. However, drug treated patients are frequently non- compliant, refractory and/or suffer from adverse effects. Current surgical implants are passive devices unable to detect or respond to changes in IOP and frequently fail. With either approach, a patient office visit is required for the physician to manually verify IOP control by tonometry. We propose to create an implant capable of both sensing IOP and regulating it through opening and closing a miniature valve. The implant's power supply will be self- contained, with a transceiver capable of sending and receiving external commands. In its final form the implant will monitor and regulate IOP and be capable of sending IOP data and information concerning valve function to the physician and/or patient. A data collection system will also be constructed to record and document all parameters on a PC. In this Phase I feasibility study we will construct a working prototype of the valve and conduct in vitro and in vivo tests. The three specific, measurable objectives for Phase I are to: Design and fabricate a miniature twin magnetic stop/electromagnetic valve with accompanying telemetry and data acquisition system. Perform short and long-term in vitro tests of the valve to demonstrate detection, response and control of IOP in the normal and pathological pressure ranges. Implant the valve and test it both acutely and chronically on conscious, active normal IOP rabbits to determine safety and efficacy. Glaucoma, a wide spread ocular disease increases the pressure inside the eye and if left untreated causes blindness. We will create an electronically controlled valve and pressure recorder to be placed in the eye that will reduce this pressure and preserve sight. [unreadable] [unreadable] [unreadable]